Sequential channel selector simplifies software- 01/04/01 EDN Design Ideas: An efficient but powerful circuit is useful for a variety of applications with limited I/O and for which you want to use one input to sequentially select a different output channel (Figure 1 ]. When the software changes the state __ Circuit Design by Alex Knight, Cummins Engine Co, Columbus, IN

Simultaneous PCB, Silicon & Software Verification Cuts Time-to-Market, Pt.2- 05/21/01 EDN Design Ideas: A recent and important innovation in the in-circuit emulation field is the development of behavioral emulation methods. These methods connect emulation and simulation acceleration engines on a high-speed bus in order to provide gains of 100 times to 10, 00 __ Circuit Design by Ray Turner

Software avoids interrupt overhead- 03/02/00 EDN Design Ideas: You can service peripheral ICs connected to aµC by polling or via interrupts. The polling method can be time-consuming, so interrupt handling is often preferable because the µC has to take care of the peripheral only on request. __ Circuit Design by Hans-Herbert Kirste

Software Center for Design Ideas (1995-June 7, 2001)- EDN-Design Ideas-December 11, 2002 This section contains code listings and computer-readable material associated with Design Ideas published from 1995 through June 7, 2001. To find the file you need, use your browser's 'Find' function to search for 'DI####' where '####' is the reference number of the Design Ideas article in question (you can find the reference number in parentheses at the end of the article). For listings and software associated with Design Ideas published after June 7, 2001, you can find them directly in the Web versions of the Design Ideas in which they ran. __ Circuit Design by EDN Staff

Software Implements Digital Potentiometer- 06/08/95 EDN Design Ideas: In some applications (for example, dynamic biasing of laser diodes) , the use of digital potentiometers, or trimDACs, has limitations because of resolution, accuracy, or interface difficulties. Using the simple (but maybe not so obv __ Circuit Design by Gray Creager, Xicor Inc, Milpitas, CA

Software makes full use of 8051's interrupt system- 12/06/01 EDN Design Ideas: The program in Listing 1 uses a pseudo-RETI instruction to provide a five-priority-level interrupt system for the 8051P microcontroller. The interrupt-priority order, from high to low, is INT0 IT0 INT1 IT1 INTP. Before the pseudo-RETI instruction arrives in the IT0 or IT1 interrupt-service routine, the address of the first instruction, which is after the pseudo-RETI instruction, goes ba __ Circuit Design by Deng Yong, Shanghai Jiaotong University, China

Software PLL locks VCXO to reference- 08/01/98 EDN Design Ideas: ( FILE has several circuit ideas. Scroll to find this one.) The circuit in Figure 1 provide as a precisely controlled clock signal. The method modifies the controller's quartz oscillator such that the control voltage at point P1 controls the frequency. A D/A converter using an R-2R ladder network connected to output port D generates the control voltage. A precise reference-frequency signal connects to the controller's analog-comparator input, AIN0. In this application, the reference frequency is 162 kHz (derived from a long-wave broadcast station). You can use any other 10- to 200-kHz frequency. __ Circuit Design by Martin Ossmann, Philips Research Labs, Aachen, Germany

Software reset uses I²C I/O port- 05/16/02 EDN Design Ideas: You can use the circuit in Figure 1 to allow the I2C or SMBus to control device resets in a system by using the PCA9554 I2 C I/O-port IC. Normally, a reset function takes an active-low signal. On power-up of the PCA9554, the IC set __ Circuit Design by Bob Marshall, Philips Semiconductors, Sunnyvale, CA

Software routine minimizes large logic table- 07/03/97 EDN Design Ideas: You can define combinatorial logic circuitry by explicitly stating the output patterns that result from particular input patterns. Such behavioral description is sometimes more convenient than writing logic equations; virtually all logic-design systems accept table entry, among other entry formats. Unfortunately, limitations of allowable table size preclude direct minimization of large logic tables. The technique proposed here uses Espresso, a public-domain logic minimizer available from the University of California--Berkeley. __ Circuit Design by Jerzy Chrzaszcz, Warsaw University of Technology, Warsaw, Poland

Software routine stabilizes hardware register - 07/18/96 EDN Design Ideas: Microprocessor peripheral devices with multibyte registers often harbor a subtle bug that can bite the unwary software engineer. If your program reads the peripheral device's registers at the same time that the device is updating those registers, the program can obtain a mixed result. One or more of the bytes could be left over from a previous reading, __ Circuit Design by Greg Young, Z-World Engineering, Davis, CA

Software speeds 8051 RS-232C receiver- 12/04/97 EDN Design Ideas: This method allows for receiving data from a half-duplex, 9600-bps or faster serial link in an 8051-based system without using a hardware UART. The method's goal is to minimize performance degradation that software-service routines incur. Bit-cell time for 9600-bps transmission __ Circuit Design by Jerzy Chrzaszcz, Warsaw University of Technology, Poland

Solving a customer’s problem leads to a winning ide- EDN Design Ideas: 05/12/1994 To say Ken Chapman is thrilled to be the 1993 Design Ideas winner for his design "Fast integer multipliers fit in FPGAs" is an understatement. After the shock of learning he won, Chapman’s reaction was one of wonder and pride that so many people had reacted favorably to his idea. "It’s wonderful to come up with an application that people want to use," he says. The award is a nice bonus as far as Chapman is concerned, but the real excitement comes from learning that people around the world are using his design. __ Circuit Design by Susan Rose, Contributing Editor, EDN

Three-phase Programmable Controller for ON/OFF Motor- Automatic on/off controller for a 3-phase electric motor can be made with a programmable time switch. In this case a maximum of eight time durations can be programmed. The system has two...__ Electronics Projects for You

Tony Nixon’s Pocket Programmer (PIC)- Tony Nixon’s Pocket Programmer. The Pocket Programmer is a standalone serial programmer that can program most of the PICmicro®MCU range of microprocessors. (12C6xx, 16Cxxx, 16Fxxx, 18Cxxx) It works from a single 18VDC supply or with 2 X 9 volt batteries. Combine this with 64K of on board EEPROM which can store up to 32 HEX files and you have a truly portable programmer / patcher __ Designed by Seiichi Inoue

Transaction Approach to Error Handling- EDN Design Ideas: 04/28/94 You can apply the transaction-based recovery concept used in databases to any application. Doing so helps provide more reusable and maintainable programs. Programs contain two major paths: a forward path that does the work and a reverse path that rolls back the work when the program detects errors. Typically, these paths are so tightly bound together that both paths are difficult to read. Code that is difficult to read results in code that is difficult to write, debug, enhance, and reuse. __ Circuit Design by Bruce A Rafnel, Hewlett-Packard Co

Universal OS PIC Programmer- This programmer requires only a basic terminal program capable of uploading an asci PIC HEX file. It does not matter what operating system or computer (MAC, Win98, XP, Vista, DOS, Linux, etc.) is used to talk to it. __ Designed by Luhan Monat - Mesa Arizona

USB to RS232 Dongle- With serial and parallel ports being phased out on new computers, hardware designers and hobbyists have no choice but to convert the USB port back to RS232 serial. FTDI have a very nice chip that does just that, the FT232AM. This chip converts USB to a standard high-speed serial port. The bonus with FTDI is the drivers are already written for you. All you have to do is design the hardware and download the serial USB drivers from FTDI's web site. __

Visual Basic Models MDAC offset- 03/13/98 EDN Ideas - ( FILE has several circuits, scroll to this one) It's hard to imagine that, for such an old-hat item as a standard R-2R multiplying DAC (MDAC], there still exists some "dark area" in modeling and calculating its dc offset, VOFF, and related output resistance, RO. You can obtain some information from References 1and 2 and other references regarding the code dependency of RO and VO, but the simplified formulas Page includes several designs. Scroll to find this one __ Circuit Design by Olga Belousava, Los Alamos, NM, and Alex Belousov, New York, NY